POS0554 ANTIPHOSPHOLIPID ANTIBODIES AND VASCULAR THROMBOSIS IN PATIENTS WITH THE MOST SEVERE FORMS OF COVID-19
Authors: M. Zlatkovic-Svenda, M. Zdravković, M. Ovuka, M. Ogrič, S. Čučnik, P. Zigon
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> The presence of antiphospholipid antibodies (aPL) has been observed in patients with COVID-19 (1,2), suggesting that they may be associated with deep vein thrombosis, pulmonary embolism, or stroke in severe cases (3). Antiphospholipid syndrome (APS) is a systemic autoimmune disorder and the most common form of acquired thrombophilia globally. At least one clinical criterion, vascular thrombosis (arterial, venous or microthrombosis) or pregnancy morbidity and at least one laboratory criterion- positive aPL two times at least 12 weeks apart: lupus anticoagulant (LA), anticardiolipin (aCL), anti-β2-glycoprotein 1 (anti-β2GPI) antibody, have to be met for international APS classification criteria(4). Several reports also associate anti-phosphatidylserine/prothrombin antibodies (aPS/PT) with APS. <h3>Objectives</h3> To combine clinical data on arterial/venous thrombosis and pregnancy complications before and during hospitalisation with aPL laboratory findings at 4 time points (hospital admission, worsening of COVID-19, hospital discharge, and follow-up) in patients with the most severe forms of COVID-19 infection. <h3>Methods</h3> Patients with COVID-19 pneumonia were consequetively enrolled, as they were admitted to the General hospital Pancevo. Exclusion criteria were previous diagnosis of inflammatory rheumatic disease and diagnosis of APS. Clinical data were obtained from the medical records. Laboratory results, including LA, aCL, anti-β2GPI, and aPS/PT antibodies were taken at hospital admission, worsening (defined as cytokine storm, connection of the patient to the respirator, use of the anti-IL-6 drug- Tocilizumab), at hospital discharge and at 3-months follow-up and sent to University Medical Centre Ljubljana, Slovenia for analysis. Statistics was performed by using SPSS 21. <h3>Results</h3> 111 patients with COVID-19 pneumonia were recruited; 7 patients died during hospitalisation (none were aPL-positive on admission and at the time of worsening), 3 due to pulmonary artery embolism. All patients were treated according to a predefined protocol which included antibiotics, corticosteroids, anticoagulation therapy and specific comorbidity drugs; patients with hypoxia were supported with oxygen. During hospitalisation, pulmonary artery thrombosis occurred in 5 patients, one was aPL-positive at all time points (was diagnosed with APS), others were negative. In addition, 9/101 patients had a history of thrombosis (5 arterial thrombosis (coronary and cerebral arteries), none of whom was aPL-positive on admission and at follow-up, and 4 venous thrombosis, one of which was aPL-positive at all time points and received an APS diagnosis). Among 9/101 patients with a history of thrombosis, 55.6% were transiently positive at the time of discharge, compared to patients without prior thrombosis, in whom 26.1% were transiently positive at the hospital release (p=0.074). Two patients had a history of pregnancy complications (both had miscarriage after 10th week of gestation), but did not have aPL positivity at any time point. <h3>Conclusion</h3> Although aPL was expected to be associated with vascular disease in the most severe forms of COVID-19, all patients that have died in our cohort were aPL negative. At hospital discharge, 56% of patients with a history of arterial or venous thrombosis had positive aPL that became negative at the 3-months follow-up (were transienlty positive), which should be considered when prescribing therapy after hospitalisation. <h3>References</h3> [1]Trahtemberg U, Rottapel R, Dos Santos CC<i>, et al.</i> Anticardiolipin and other antiphospholipid antibodies in critically ill COVID-19 positive and negative patients. <i>Annals of the Rheumatic Diseases</i> 2021;80:1236-1240. [2]Stelzer M, Henes J, Saur S. The Role of Antiphospholipid Antibodies in COVID-19. <i>Curr Rheumatol Rep</i>. 2021;23(9):72-4. [3]Xie Y, Wang X, Yang P, Zhang S. COVID-19 complicated by acute pulmonary embolism. Radiology: <i>Cardiothoracic Imaging</i> 2020: 2: e200067. [4]Miyakis S, Lockshin MD, Atsumi T, Branch DW, Brey RL, et al. <i>J.Thromb.Haemost.</i> 2006; 4: 295-306. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.